A number of power equipments have been produced to facilitate forming a work piece into a desired shape. One such power equipment is a table saw. A wide range of table saws are available for a variety of uses. Some table saws such a cabinet table saws are very heavy and relatively immobile. Other table saws, sometimes referred to as jobsite table saws, are relatively light. Jobsite table saws are thus portable so that a worker can position the table saw at a job site. Some accuracy is typically sacrificed in making a table saw sufficiently light to be mobile. The convenience of locating a table saw at a job site, however, makes job site table saws very desirable in applications such as general construction projects.
All table saws, including cabinet table saws and job site table saws, present a safety concern because the blade is moving at an extremely high speed with a significant torque. A work piece can be thrown back at a user by a rotating blade causing injury and ruining the work piece if safety devices are not used. The potential for such “kickback” is compounded by the fact that the blade makes a very narrow cut in the work piece. Accordingly, even a slight skewing of the work piece or even cut closing from tension in the work piece can create binding between the blade and the work piece, resulting in kickback. Additionally, some work pieces are not perfectly flat. Consequently, the portion of the work piece which has been cut can twist, causing binding with the blade.
One device which has been developed to reduce the potential for kickback is referred to as a riving knife. A riving knife is located at the rear portion of the table saw, after the blade. The riving knife is aligned with the blade. Accordingly, as the blade cuts the work piece, a “cut” (gap between adjacent cut portions of the work piece) is formed by the blade and the cut is aligned with the riving knife. Consequently, as the work piece is advanced, the riving knife is positioned in the cut, thereby precluding the cut from closing and binding on the blade.
While riving knives are helpful in reducing the potential for kickback, kickback can still occur. Accordingly, a number of table saws are equipped with anti-kickback devices. Anti-kickback devices are typically mounted on the riving knife or a blade guard and consist of two toothed pawls which allow the work piece to move in a single direction in the cutting direction of the saw. Any movement of the work piece in a direction opposite to the cutting direction forces the work piece into the teeth of the pawls which restrict further movement.
Anti-kickback devices are very effective at minimizing the danger posed by kickback. There are some shaping operations with cosmetic surfaces, however, which are not easily accomplished when an anti-kickback device is installed. Accordingly, users frequently have occasion to remove the anti-kickback devices for storage and transportation. Many such devices require both hands tools to remove the anti-kickback devices.
Another disadvantage of known anti-kickback devices is the complexity and cost of such devices. A number of components are required in order to properly mount the assembly to a riving knife or blade guard. The increased number of components increases the time and costs associated with manufacturing the anti-kickback device.
In view of the foregoing, it would be advantageous to provide a power tool with an anti-kickback device that is easily removed and installed with one hand. An anti-kickback device with a reduced number of components would also be advantageous.